Background The optimal position for continuous adductor canal block (ACB) for analgesia after total knee anthroplasty (TKA) remians controversial, mainly due to high variability in the localization of the the adductor canal (AC). Latest neuroanatomy studies show that the nerve to vastus medialis plays an important role in innervating the anteromedial aspect of the knee and dives outside of the exact AC at the proximal end of the AC. Therefore, we hypothesized that continuous ACB at the proximal end of the exact AC could provide a better analgesic effect after TKA compared with that at the middle of the AC (which appeared to only block the saphenous nerve). Methods Sixty-two adult patients who were scheduled for a unilateral TKA were randomized to receive continuous ACB at the proximal end or middle of the AC. All patients received patient-controlled intravenous analgesia with sufentanil postoperatively. The primary outcome measure was cumulative sufentanil consumption within 24 h after the surgery, which was analyzed using Mann-Whitney U tests. P-values < 0.05 (two-sided) were considered statistically significant. The secondary outcomes included postoperative sufentanil consumption at other time points, pain at rest and during passive knee flexion, quadriceps motor strength, and other recovery related paramaters. Results Sixty patients eventually completed the study (30/group). The 24-h sufentanil consumption was 0.22 μg/kg (interquartile range [IQR]: 0.15–0.40 μg/kg) and 0.39 μg/kg (IQR: 0.23–0.52 μg/kg) in the proximal end and middle groups (P = 0.026), respectively. There were no significant inter-group differences in sufentanil consumption at other time points, pain at rest and during passive knee flexion, quadriceps motor strength, and other recovery related paramaters. Conclusions Continuous ACB at the proximal end of the AC has a better opioid-sparing effect without a significant influence on quadriceps motor strength compared to that at the middle of the AC after TKA. These findings indicates that a true ACB may not produce the effective analgesia, instead, the proximal end AC might be a more suitable block to alleviate pain after TKA. Trial registration This study was registered at ClinicalTrials.gov (NCT03942133; registration date: May 06, 2019; enrollment date: May 11, 2019).

BackgroundThe microbiota of both humans and animals plays an important role in their health and the development of disease. Therefore, the bacterial flora of the conjunctiva may also be associated with some diseases. However, there are no reports on the alteration of bacterial flora in conjunctiva of diabetic rats in the literature. Therefore, we investigated the changes in bacterial flora in bulbar conjunctiva of rats with streptozotocin (STZ)-induced type I diabetes.MethodsA high dose of STZ (60 mg/kg, i.p.) was injected into Sprague-Dawley (SD) rats to induce type I diabetes mellitus (T1DM). The diabetic rats were raised in the animal laboratory and at 8 months post-injection of STZ swab samples were taken from the bulbar conjunctiva for cultivation of aerobic bacteria. The bacterial isolates were identified by Gram staining and biochemical features. The identified bacteria from both diabetic and healthy rats were then compared.ResultsThe diabetic and healthy rats had different bacterial flora present in their bulbar conjunctiva. In total, 10 and 8 bacterial species were found in the STZ and control groups, respectively, with only three species (Enterococcus faecium, Enterococcus gallinarum and Escherichia coli) shared between the two groups. Gram-positive bacteria were common in both groups and the most abundant was Enterococcus faecium. However, after the development of T1DM, the bacterial flora in the rat bulbar conjunctiva changed considerably, with a reduced complexity evident.ConclusionsSTZ-induced diabetes caused alterations of bacterial flora in the bulbar conjunctiva in rats, with some bacterial species disappearing and others emerging. Our results indicate that the conjunctival bacterial flora in diabetic humans should be surveyed for potential diagnostic markers or countermeasures to prevent eye infections in T1DM patients.

Background Quadratus lumborum block (QLB) is increasingly gaining popularity as a novel abdominal truncal block in abdominal surgery; however, the mechanism of QLB is not yet thoroughly illustrated. The focus of our study is transmuscular QLB (TMQLB), as the latest anatomical evidence shows that anesthetics spread into the thoracic paravertebral space to exert an analgesic effect. Therefore, we designed this study to compare TMQLB with thoracic paravertebral block (TPVB) in laparoscopic renal surgery in the hope of providing clinical evidence on the analgesic mechanism of TMQLB and its application in laparoscopic renal surgery. Methods This trial is a prospective, randomized, single-center, open-label, parallel, three-arm, non-inferiority trial. We intend to include 120 participants undergoing laparoscopic nephrectomy and before surgery they will be randomized into three groups for postoperative pain control: TMQLB experimental group 1 (0.4 ml/kg body weight 0.5% ropivacaine), TMQLB experimental group 2 (0.6 ml/kg body weight 0.5% ropivacaine) or TPVB control group (0.4 ml/kg body weight 0.5% ropivacaine at vertebra T10). Patients will be excluded if they have allergy to anesthetics, infection at the injection site, are on coagulopathy or anticoagulants, on analgesics for chronic illness, have history of substance abuse or have a barrier to communication. Morphine is given in boluses of 1.5~2 mg by intravenous patient-controlled analgesia (IPCA) in the first 48 h after surgery. The primary outcome is the difference between TMQLB group 1 and the TPVB group in the mean visual analogue scale (VAS) pain score in the first 24 h after surgery. Secondary outcomes are the difference between TMQLB group 2 and the TPVB group in the mean VAS score in the first 24 h after surgery, cumulative morphine consumption, long-term pain control, dermatomal distribution of sensory loss, nausea score, pruritus score, ambulation time, time till recovery of bowel movement, quality of recovery, postoperative length of hospital stay and patient satisfaction with anesthesia. Safety data on procedure-related complications will also be summarized. Discussion This will the first randomized controlled trial to compare TMQLB with TPVB for analgesia in laparoscopic surgery. This trial aims to provide important clinical evidence to elaborate on the analgesic mechanism of TMQLB. Trial registration ClinicalTrials.gov, NCT03414281 . Registered on 9 January 2018. Electronic supplementary material The online version of this article (10.1186/s13063-019-3359-7) contains supplementary material, which is available to authorized users.

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